Binding agents or, as they are sometimes known, thickeners form the base of many dried food products such as sauces, soups and gravies. These dried food products usually contain other ingredients such as dried vegetables, meat extracts, yeast extracts, sugars, salt, fats, oils and the like but it is the binding agent that usually gives the food, once re-hydrated, its consistency and creamy sensory appeal. The idea is for the binding agent to simulate the roux used in traditional cooking.
Like roux, the binding agents are usually prepared from a starch material and a fat. The starch material is usually in the form of a flour of some sort; particularly wheat flour although other flours are used. Now-a-days the fat is usually a hardened vegetable fat. The starch material and the fat are combined, often dehydrated, and then added to the remaining ingredients of the dried food product. However, severe problems have arisen in providing a binding agent which, when hot water is stirred into the dried food product, does not result in lumping or clumping. If the product is intended as an "instant food", it is important that the dried food product re-hydrate rapidly upon the addition of hot water without lumping or clumping.
The problem was addressed in U.S. Pat. No. 4,363,824. This patent describes a process in which a high melting point fat is first heated to above its melting point (for example to 70.degree. C.). A flour is then mixed in to provide a dough containing about 55% to 80% flour. The dough is then transported to a cooling tank where it is allowed to cool under controlled conditions. In particular, the dough undergoes cooling so that a constant temperature decrease occurs at least while the dough is at a temperature between 35.degree. C. and 15.degree. C. Cooling in this manner causes the fats to undergo crystal structure modifications and results in a product which contains less than 50% liquid fat when at a temperature of 20 to 35.degree. C. The cooled dough is then run through a cooling roller to form it into a thin sheet. The dough is then scraped off in the form of flakes. The flakes are then added to dried foodstuffs as the binding agent. The binding agents produced by this process provide the dried foodstuffs with good re-hydration properties. However, the binding agents contain relatively high amounts of fatty material in order for them to be processed through the cooling roller. In certain cases, for example if the binding agent is to be used for low fat products, this may be disadvantageous.
Another approach is described in U.S. Pat. No. 4,568,551. This patent describes a process in which a high melting point fat is heated to melt it and the melt is then mixed with a starch material, particularly wheat flour, to form a homogeneous dough. A small amount of water is then mixed in. The dough is then heated to a temperature above 90.degree. C. and maintained at the elevated temperature, under continuous mixing, until the moisture content reduces to below 7%. The dough is then cooled to room temperature and ground up to form a free-flowing, dehydrated, binding agent. The binding agent is described to disperse readily in boiling water without the formation of lumps. The disadvantage of this process is that it requires heating to above 90.degree. C., in many cases for long periods. This makes the process expensive.
Yet another process is described in British patent 1478843. In the process described in this patent, an agglomerated starch is coated with an edible fat of high melting point in a planetary mixer or bowl chopper. The process has the advantage of being simple and no heating or cooling is required. Also the fat content of the binding agent may be low; for example about 20% by weight. However the binding agent is not made up of well formed particles and the flowability of the binding agent is low.
Therefore there is a need for a binding agent for foodstuffs which is flowable, readily dispersible in water, which may contain relatively low amounts of fatty materials, and which may be produced by a process not requiring the use of high temperatures.